MD03 - 24V 20A H Bridge Motor Driver

Devantech

The MD03 is a medium power motor driver, designed to supply power beyond that of any of the low power single chip H-Bridges that exist. Main features are ease of use and flexibility. The motor's power is controlled by on-board Pulse Width Modulation (PWM) generators driving the H-Bridge Transistors.

Overview

MD03
Voltage	5v logic supply and 5v - 24v for the motor
Current	50mA Max for logic and up to 20A for the motor
Control 1	0v - 2.5v - 5v Analogue for Reverse - Stop - Forward
Control 2	0v - 5v (or PWM equiv.) with separate direction control
Control 3	RC Mode - Controlled by standard Radio Control system. Direct connection to RC receiver. (1mS - 2mS pulse with 1.5mS center off).
Control 4	I2C Interface, full control, acceleration and status reporting. Up to 8 modules on bus. SCL speed up to 1MHz
Current limiter	Preset at 20A
Temperature limiter	Reduces power gracefully if module overheats
Size	113mm x 52mm x 30mm

Main features are ease of use and flexibility. The motor's power is controlled by Pulse Width Modulation (PWM) of the H-Bridge at a frequency of 15khz ( 7.5khz before version 12).
The 15v MOSFET drive voltage is generated onboard with a charge pump, so the module requires only two supply voltages

1. A standard 5V supply for the control logic, only 50mA maximum is required.
2. The H-Bridge has a rating of 60v allowing Motor voltages up to 24vdc.

Control of the module can be any of

1. I2C bus, up to 8 MD03 modules, switch selectable addresses.
2. 0v-2.5-5v analog input. 0v full reverse, 2.5v center stop, 5v full forward.
3. 0v-5v analog input with separate direction control
4. RC mode. Controlled directly from the RC receiver output.
5. PWM. A simple onboard filter means you can use a 0%-100% 20khz or greater instead of analog.

Motor connections

There is no fuse on the PCB. You should provide a 25/30A fuse in line with the +v battery terminal.
Don't Ignore this, High currents can be dangerous!

Motor Noise Suppression

Please note that using motors with the MD03 as with any other electronic device requires suppression of noise. This is easily achieved by the addition of a 10n snubbing capacitor across the motor. The capacitor should also be capable of handling a voltage of twice the drive voltage to the motor.

Control Connections

The connections for use with the I2C Bus are marked on the PCB.

General Usage

The MD03 can handle high currents, and you will need to take a few precautions with wiring. It is very important that you do not allow motor current to flow in the logic ground path. Don't assume that just because the Battery, MD03 and Controller grounds are all together, that all is well. If at all possible, use two batteries, one for the logic and and the other for the motor power. Don't connect the battery grounds together, that is already done on the MD03. If you do, then you will only create a ground loop - and problems. The diagram below shows the general idea on keeping the logic and power sides electrically and physically separate from each other.

Manufacturer's data

Technical Specification - link to the manufacturer

Product information for: MD03 H-Bridge - Motor driver

Publishing date (date of last technical specification): 2010-10-10
Weight: 130 g
Shipping weight: 230 g
Manufacturer: Devantech
Brand: ROBOT ELECTRONICS
Article number: DEV-MD03
Manufacturer's part number: MD03

The article MD03 H-Bridge - Motor driver is listed in the following categories:

Drives > Motor control